The packages xwatermark cannot work correctly when change the page numbering style! For example, when using the pages=0-2 option, the watermark will be inserted the first two pages after every change numbering style not the the first two pages of whole document. When using allpages option, the latex will complain that
"Missing number, treated as zero".
How to solve the problem? I make an apology for my poor English.
\documentclassand the appropriate packages that sets up the problem. While solving problems can be fun, setting them up is not. Then, those trying to help can simply cut and paste your MWE and get started on solving the problem. – Peter Grill Feb 24 at 7:24